This commit moves the lost fine logic out of the lost processing
portion of Circulate.pm and into the new handle_fines() method.
This is accomplished through setting a new flag and lost
options hash on the main Circulator object.

This change improves the overall process flow, and in doing so
addresses a bug where overdue fines could be doubled if both
restore-overdue-on-lost-return and generate-new-overdues-on-lost-return
are enabled. Before this change, the new fines would generate before
the old fines were unvoided, which effectively circumvented the max
fines setting.

A secondary change made here is that stop_fines is also now being set
during the handle_fines() stage. This improves any case where overdues
are being set on checkin, particularly lost returns, as the stop_fines
will end up as the proper value of MAX_FINES or CHECKIN.